moar scripts

2026-04-15 00:42:18 -04:00
parent 63ff58b3dc
commit ecce010642
2 changed files with 183 additions and 0 deletions
@@ -0,0 +1,96 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  cat <<EOF
+Usage: lab-mount <container|user> <host-path> [container-path]
+
+Bind-mounts a host directory into an LXC container, persisting across reboots.
+If container-path is omitted, it mirrors host-path inside the container.
+
+Examples:
+  lab-mount alice /mnt/nas/shared              # -> /mnt/nas/shared inside lxc-alice
+  lab-mount alice /mnt/nas/shared /data/shared  # -> /data/shared inside lxc-alice
+  lab-mount lxc-alice /mnt/nas/shared           # container name directly also works
+
+To mount for ALL containers:
+  lab-mount --all /mnt/nas/shared /data/shared
+EOF
+  exit 1
+}
+
+mount_into() {
+  local CONTAINER="$1"
+  local HOST_PATH="$2"
+  local CONT_PATH="$3"
+  local ROOTFS="/var/lib/lxc/${CONTAINER}/rootfs"
+  local CONFIG="/var/lib/lxc/${CONTAINER}/config"
+
+  if [[ ! -d "$ROOTFS" ]]; then
+    echo "ERROR: container '$CONTAINER' not found" >&2
+    return 1
+  fi
+
+  if [[ ! -e "$HOST_PATH" ]]; then
+    echo "ERROR: host path '$HOST_PATH' does not exist" >&2
+    return 1
+  fi
+
+  # create mountpoint inside rootfs
+  mkdir -p "${ROOTFS}${CONT_PATH}"
+
+  # check if this bind mount is already in config
+  local ENTRY="lxc.mount.entry = ${HOST_PATH} ${CONT_PATH#/} none bind,create=dir 0 0"
+  if grep -qF "$ENTRY" "$CONFIG" 2>/dev/null; then
+    echo "Already configured: ${CONTAINER} ${HOST_PATH} -> ${CONT_PATH}"
+    return 0
+  fi
+
+  # add persistent bind mount to container config
+  echo "$ENTRY" >> "$CONFIG"
+  echo "Added to config: ${CONTAINER} ${HOST_PATH} -> ${CONT_PATH}"
+
+  # if the container is running, also mount it live
+  local STATE
+  STATE=$(lxc-info -n "$CONTAINER" -sH 2>/dev/null || true)
+  if [[ "$STATE" == "RUNNING" ]]; then
+    # lxc-attach to mount from inside
+    lxc-attach --clear-env -n "$CONTAINER" -- /bin/bash -c "
+      export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+      mkdir -p '${CONT_PATH}'
+    "
+    # note: live bind mounts into running unprivileged containers via config
+    # may require a container restart to take effect
+    echo "NOTE: restart the container for the mount to take effect:"
+    echo "  lxc-stop -n ${CONTAINER} && lxc-start -n ${CONTAINER}"
+  fi
+}
+
+resolve_container() {
+  local NAME="$1"
+  # if it already starts with lxc-, use as-is
+  if [[ "$NAME" == lxc-* ]]; then
+    echo "$NAME"
+  elif [[ -f "/home/${NAME}/.lxc-container" ]]; then
+    cat "/home/${NAME}/.lxc-container"
+  else
+    echo "lxc-${NAME}"
+  fi
+}
+
+# --- parse args ---
+[[ $# -lt 2 ]] && usage
+
+if [[ "$1" == "--all" ]]; then
+  HOST_PATH="$2"
+  CONT_PATH="${3:-$HOST_PATH}"
+  for dir in /var/lib/lxc/lxc-*/; do
+    CONTAINER=$(basename "$dir")
+    mount_into "$CONTAINER" "$HOST_PATH" "$CONT_PATH"
+  done
+else
+  CONTAINER=$(resolve_container "$1")
+  HOST_PATH="$2"
+  CONT_PATH="${3:-$HOST_PATH}"
+  mount_into "$CONTAINER" "$HOST_PATH" "$CONT_PATH"
+fi